Eddy current testing of weld penetration of rocket engine injector

The injector serves is a critical component in liquid rocket engine combustion chambers. Numerous electron beam welds exist in injectors, where weld penetration depth directly affects injector reliability and may impact the safe and stable operation of rocket engines. Addressing the lack of effective detection and evaluation methods for electron beam weld penetration quality in rocket engine injectors, this study investigated the effectiveness of eddy current testing methods. First, numerical simulations of electron beam weld penetration eddy current testing were conducted using edge finite element methods based on reduced magnetic vector potentials, analyzing the feasibility and sensitivity of Pancake and TR configuration eddy current probes for evaluating weld penetration. Subsequently, based on simulation results, specially designed Pancake and TR eddy current probes for injector weld inspection were fabricated, with experiments further validating the feasibility of eddy current methods for evaluating electron beam weld penetration. Results indicated that Pancake probes exhibited higher sensitivity for weld penetration detection, confirming that eddy current methods could effectively evaluate electron beam weld penetration in injectors.